CHARACTERIZATION OF DOUBLE-DIFFUSED ARSENIC PHOSPHORUS SHALLOW N+P JUNCTIONS WITH TISI2

This paper investigates the fabrication of titanium silicided, As/P shallow junctions. Diodes were characterized electrically and analyzed by secondary ion mass spectroscopy, Rutherford back scattering, and transmission electron microscopy. The effect of silicide formation on the quality of shallow junctions has been studied. We employed rapid thermal annealing to drive the junctions in order to minimize the defect enhanced diffusion of P. The shallowest junctions were made by 2 x 10(15) cm-2 50 keV As followed by 5 x 10(13) cm-2 25 keV P and activation of the dopants with a 1050-degrees-C, 10 s rapid thermal annealing (RTA). The junction depth for this case was approximately 1800 angstrom (from TiSi2 surface). Junctions received an additional low temperature furnace annealing after the RTA step to reduce the junction leakage. Diodes showed low leakage <5 nA/CM2 at 5 V reverse bias.